001/*002// This software is subject to the terms of the Eclipse Public License v1.0003// Agreement, available at the following URL:004// http://www.eclipse.org/legal/epl-v10.html.005// You must accept the terms of that agreement to use this software.006//007// Copyright (C) 2004-2005 TONBELLER AG008// Copyright (C) 2006-2009 Pentaho and others009// All Rights Reserved.010*/011package mondrian.rolap.sql;012013/**014 * Restricts the members that are fetched by SqlMemberSource.015 *016 * @see mondrian.rolap.SqlMemberSource017 *018 * @author av019 * @since Nov 2, 2005020 */021public interface SqlConstraint {022023 /**024 * Returns a key that becomes part of the key for caching the025 * result of the SQL query. So SqlConstraint instances that026 * produce the same SQL resultset must return equal keys027 * in terms of equal() and hashCode().028 * @return valid key or null to prevent the result from being cached029 */030 Object getCacheKey();031}032033// End SqlConstraint.java